How accurate are pregnancy test results? Pregnancy test strips are a common tool used to detect whether a woman is pregnant. The detection principle is to check the level of human chorionic gonadotropin (hCG) in a woman\’s urine. If hCG is detected, it means that the woman is pregnant. So, how accurate are pregnancy tests? The first thing to make clear is that the accuracy of pregnancy test strips is affected by many factors, such as